- 您现在的位置：买卖IC网 > PDF目录382330 > MM5486 (National Semiconductor Corporation) LED Display Driver PDF资料下载
参数资料
| 型号： | MM5486 |
| 厂商： | National Semiconductor Corporation |
| 英文描述： | LED Display Driver |
| 中文描述： | LED显示驱动器 |
| 文件页数： | 3/8页 |
| 文件大小： | 168K |
| 代理商： | MM5486 |
Functional Description
The MM5486 is specifically designed to operate four-digit
alphanumeric displays with minimal interface with the dis-
play and the data source. Serial data transfer from the data
source to the display driver is accomplished with 3 signals,
serial data, clock, and load. The data bits are latched by a
positive-level load signal, thus providing non-multiplexed, di-
rect drive to the display. When load is high, the data in the
shift registers is displayed on the output drivers. Outputs
change only if the serial data bits differ from the previous
time. Display brightness is determined by control of the out-
put current for LED displays. A 0.001
m
F capacitor should
be connected to brightness control, pin 19, to prevent possi-
ble oscillations. The output current is typically 20 times
greater than the current into pin 19, which is set by an exter-
nal variable resistor. There is an internal limiting resistor of
400
X
nominal value.
A block diagram is shown in Figure 1.
Figure 4 shows the input data format. Bit ‘‘1’’ is the first bit
into the data input pin and it will appear on pin 17. A logical
‘‘1’’ at the input will turn on the appropriate LED. The load
signal latches the 33 bits of the shift register into the latch-
es. The data out pin allows for cascading the shift registers
for more than 33 output drivers.
When the chip first powers ON, an internal power ON reset
signal is generated which resets all registers and latches.
The leading clock returns the chip to its normal operation.
Figure 3 shows the timing relationship between data, clock
and data enable. A maximum clock frequency of 0.5 MHz is
assumed.
For applications where a lesser number of outputs are used,
it is possible to either increase the current per output, or
operate the part at higher than 1V V
OUT
. The following
equation can be used for calculations:
T
J
e
(V
OUT
) (I
LED
) (No. of segments) (
i
JA
)
a
T
A
where:
T
J
e
junction temperature, 150
§
C max.
V
OUT
e
the voltage at the LED driver outputs
I
LED
e
the LED current
i
JA
e
thermal coefficient of the package
T
A
e
ambient temperature
i
JA
(Socket Mount)
e
54
§
C/W
i
JA
(Board Mount)
e
49
§
C/W
The above equation was used to plotFigure 6, Figure 7, and
Figure 8.
TL/F/6142–3
FIGURE 3
TL/F/6142–4
*
This leading clock is necessary only after power ON.
FIGURE 4. Input Data Format
TL/F/6142–5
FIGURE 5
3
相关PDF资料 |
PDF描述 |
|---|---|
| MM5486N | LED Display Driver |
| MM5486V | LED Display Driver |
| MM54C08 | Quad 2-Input AND Gate(四路二输入与门) |
| MM74C08 | Quad 2-Input AND Gate(四路二输入与门) |
| MM54C14 | Hex Schmitt Trigger(六路施密特触发器) |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MM5486 DIE | 制造商:Texas Instruments 功能描述: |
| MM5486N | 制造商:NSC 制造商全称:National Semiconductor 功能描述:LED Display Driver |
| MM5486V | 制造商:NSC 制造商全称:National Semiconductor 功能描述:LED Display Driver |
| MM54C00 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Quad 2-Input NAND Gate, Quad 2-Input NOR Gate, Hex Inverter, Triple 3-Input NAND Gate, Dual 4-Input NAND Gate |
| MM54C00J/883 | 制造商:National Semiconductor Corporation 功能描述:NAND Gate 4-Element 2-IN CMOS 14-Pin CDIP 制造商:QP Semiconductor 功能描述:MMS54C00/M NSC DIE DIP |
发布紧急采购，3分钟左右您将得到回复。